Remove unnecessary condition

[vweevers]

subleveldown/leveldown.js

Lines 89 to 96 in 3e8c1af

	var subdb = reachdown(self.db, 'subleveldown')
	if (subdb && subdb.prefix) {
	self.prefix = subdb.prefix + self.ownPrefix
	self.leveldown = subdb.leveldown
	} else {
	self.leveldown = reachdown(self.db, matchdown, false)
	}

The && subdb.prefix here should not be needed, because at this point we've already determined subdb to be a subleveldown instance and such an instance always has a prefix (even when the user passes in an empty prefix).

If it doesn't have a prefix, that's either a bug or incorrect usage (someone modifying the prefix). Either way it should be surfaced as an error, which is preferable to hitting the else branch on L94, which can result in an incorrect self.leveldown.

[vweevers]

No longer relevant after #89.